• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제20권4호
• /
• pp.373-378
• /
• 1998

In the midfacial fracture, the orbital region presents many additional complication unique to the orbit. Among them are ectropion, entropion, lid ptosis, injury to the lacrimal apparatus, diplopia or the late development of enophthalmos. The residual problem confronting the surgen is usually enophthalmos or diplopia. Enophthalmos becomes cosmetically obvious at 3mm and if more severe it can interfere with vision from obstruction by the orbital rim. In this clinical situation, many patients prefer the simpler intraorbital volume expansion to the more complex orbital osteotomy. In general, except in mild cases of enophthalmos, the procedure of choice is osteotomy and repositioning for zygoma fracture and volume augmentation for blow-out fracture. Late treatment is performed by volume augmentation based on the CT findings behind the axis of the globe. Inferiorly placed grafts elevate the globe, posterior superior grafts move the globe anterior and medially positioned grafts push the globe laterally. In this two cases, the patients who has stable orbitozygomatic rim, the use of calvarial bone grafts more than 3 areas around intraorbital content, we corrected late enophthalmos combined with diplopia. As result, the first patient had 2mm advance in exophthalmometric check with improvement of the diplopia gradually. The second patient had 1.5mm advance with correction of vertical ocular dystopia and cosmetically good results respectively.

• Journal of Power Electronics
• /
• 제13권4호
• /
• pp.592-599
• /
• 2013

This paper investigates a new isolated single-phase AC-DC converter, which integrates a modified AC-DC buck-boost converter with a DC-DC forward converter. The front semi-stage is operated in discontinuous conduction mode (DCM) to achieve an almost unity power factor and a low total harmonic distortion of the input current. The rear semi-stage is used for step-down voltage conversion and electrical isolation. The front semi-stage uses a coupled inductor with the same winding-turn in the primary and secondary sides, which is charged in series during the switch-on period and is discharged in parallel during the switch-off period. The discharging time can be shortened. In other words, the duty ratio can be extended. This semi-stage can be operated in a larger duty-ratio range than the conventional AC-DC buck-boost converter for DCM operation. Therefore, the proposed converter is suitable for universal input voltage (90~264 $V_{rms}$) and a wide output-power range. Moreover, the voltage stress on the DC-link capacitor is low. Finally, a prototype circuit is implemented to verify the performance of the proposed converter.

• Archives of Plastic Surgery
• /
• 제35권1호
• /
• pp.92-95
• /
• 2008

Purpose: Heterotopic ossification in pressure sore patients is reported to rarely develop, but once it occurs, it frequently causes joint stiffness and mobilization restriction. The aim of this article is to report our experience of atypical bone growing at femur neck fracture site with chronic, extensive pressure sore in patient with paraplegia secondary to spinal injury. Methods: A 28-year-old male patient presented with atypical bone growth at femur neck fracture site with pressure sore. He had undergone atypical growth bone removal and separation of united iliac bone and femur, and then pressure sore was covered by advanced rotation flap. Results: The patient mobilized hip joint and rode in a wheelchair. Complications such as dehiscence, infection, hematoma and flap necrosis did not occur. Conclusion: We experienced successful correction of atypical bone growth removal and recovery of pressure sore. We report our experience of atypical bone growth of fracture site and the related literature was reviewed.

• Archives of Plastic Surgery
• /
• 제36권2호
• /
• pp.194-199
• /
• 2009

Purpose: The orbital fat buldging may cause irregular contour of lower eyelid, which is not youthful appearance. The conventional method of fat excision may cause the eyeball to move backward and downward, making enopthalmia is inevitable. The transcutaneous approach to reach the orbital septum can increase the risks of scleral show resulting from scarification at the level of the septum orbicularis junction and damaging the vertical motor branches of the preseptal orbicularis oculi muscle of the lower eyelid. Method: From July 2007 to March 2008, total of 21 patients underwent transconjunctival capsulopapebral fascia fixation procedure. In 8 patients, the herniated fat pad of the lower eyelid was relocated back into the orbit without external skin excision using capsulopalpebral fascia fixation. But in 13 patients, excision of redundant skin of the lower eyelid was performed using pinching technique, not involving orbicularis oculi muslce. In 5 patients, lateral canthotomy was done bilaterally for good visual field. In 6 patients, lateral canthopexy was also combined to correct loosening of lower eyelid. Results: Most of the patients were satisfied after at least 5 months of follow up. No patient showed scleral show. But 2 patients complained of undercorrection slightly, without secondary operation in 1 patient and re - capsulopalpebral fascia fixtation through transconjunctival approach in another patient. Conclusion: Orbital fat repositioning using transconjunctival capsulopalpebral fascia fixation is a good procedure to show youthful appearance without increasing the risk of scleral show and also showed fast recovery compared to the conventional transcutaneous approach.

• 대한두개안면성형외과학회지
• /
• 제17권2호
• /
• pp.51-55
• /
• 2016

Background: Nasal bone fractures are managed by closed reduction within the 2-week period, and are managed by secondary correction after this time. There is little literature on the delayed reduction for nasal bone fractures beyond the 2-week duration. We report our experience with nasal fractures, which were reduced beyond this period. Methods: A retrospective review was performed for all patients who had undergone closed reduction of isolated nasal bone fracture. Patients were included for having undergone reduction of nasal bone fractures at or more than 2 weeks after the injury. Medical records were reviewed for demographic information, injury mechanism, fracture type, delay in treatment, and cause for delay. Postoperative outcomes were evaluated using computed tomography images. Results: The review identified 10 patients. The average reduction time was 22.1 days. Five of patients underwent reduction between days 15 and 20, and the remaining five patients underwent reduction between days 21 and 41. The postoperative outcomes were excellent in 8 patients and good in 2 patients. Conclusion: Outcomes were superior for nasal fractures with displaced end plates and multiple fracture segments. Our study results appears to support delayed reduction of isolated nasal fractures in the presence of factors that delay bony reunion.

• Journal of Yeungnam Medical Science
• /
• 제6권1호
• /
• pp.133-140
• /
• 1989

선천성 혹은 외상으로 인한 심한 비함몰 변형환자 4례에서 자가두개골이식을 이용하여 융비술을 시행한 결과 특별한 합병증 없이 만족할만한 결과를 얻었다.

• 전력전자학회논문지
• /
• 제24권4호
• /
• pp.237-243
• /
• 2019

A high-efficiency and small-sized switched-mode line transformer (SMLT) is proposed in this study. The conventional structure of an adapter is composed of line transformer and rectifiers. This structure has a limit in miniaturizing due to low-frequency line transformer. Another structure is composed of power factor correction (PFC) and DC/DC converter. This structure has a limit in reducing volume due to two-stage structure. As the proposed SMLT is composed of an LLC resonant converter, a high-frequency transformer can be adopted to achieve isolation standards and size reduction. This proposed structure has different operation modes in accordance with line input voltage to overcome poor line regulation. In addition, the proposed SMLT is applied to the front of a conventional PFC converter, because the SMLT output voltage is restored to rectified sinusoidal wave by using a full-bridge rectifier in the secondary side. The design of the PFC converter is easy, because the SMLT output voltage is controlled as rectified sinusoidal wave. The validity of the proposed converter is proven through a 350 W prototype.

• Journal of Power Electronics
• /
• 제19권3호
• /
• pp.691-701
• /
• 2019

To solve the problems in the contact charging of inspection robots, a wireless charging system for inspection robots and a control strategy are introduced in this paper. Circuit models of a wireless power system with a compound compensation circuit and a three-phase Class-D resonant inverter are set up based on circuit theory. An output voltage control method based on the equal spread regulation of the phase difference between adjacent phases and the parameter correction method in the primary compound compensation circuit are proposed. The dynamic characteristics of the key parameters varying with the secondary coil position are obtained to further investigate the adaptive location scheme during the access and exit processes of moving robots. Combining the output voltage control method and the adaptive location scheme, a transition control strategy for the standby and operation modes of the wireless charging systems for inspection robots is put forward to realize the system characteristics including the low standby power in the standby mode and the high receiving power in the operation mode. Finally, experiments are designed and conducted to verify the correctness of the theoretical research.

• Journal of Positioning, Navigation, and Timing
• /
• 제11권1호
• /
• pp.23-28
• /
• 2022

The eLoran system is a high-power terrestrial navigation system that is recognized as the most appropriate alternative to complement the GNSS's vulnerability to radio frequency interference. Accordingly, Korea has conducted eLoran technology development projects since 2016. The eLoran system developed in Korea provides 20 m positioning accuracy to maritime user in Incheon and Pyeongtaek harbor. To accurately calculate the position with the eLoran signal, it is necessary to apply a compensation method that mitigates the propagation delay. In this paper, we develop the compensation method to mitigate the eLoran signal propagation delay and evaluate the positioning performance in Incheon harbor. The propagation delay due to the terrain characteristics is pre-surveyed and stored in the user receiver. Real-time fluctuations in propagation delay compared to the pre-stored data are mitigated by the temporal correction generated at a nearby differential Loran station. Finally, two performance evaluation tests were performed to verify the positioning accuracy of the Korean eLoran system. The first test took place in December 2020 and the second in April 2021. As a result, the Korean eLoran service has been confirmed to provide 20 m location accuracy without GPS.

• 식품보건융합연구
• /
• 제8권1호
• /
• pp.17-20
• /
• 2022

Paralytic ileus is a metabolic state in which the intestines fail to transmit peristalsis due to failure of the neuromuscular mechanism in the small intestines and colon. It is a major cause of morbidity in hospitalized patients especially during late presentations and points of mismanagement. The causes include infections, electrolyte imbalance (hypokalemia, hyponatremia), surgeries and medications. When the exact cause of the disease condition is identified and corrected, paralytic ileus is usually resolved. This case report is that of a 16 year old female who was admitted and managed as a case of paralytic ileus. The patient presented with symptoms of fever, abdominal pain, abdominal distension, vomiting and inability to pass stool or flatus. There was associated body weakness, reduced urine output and weight loss. She was properly examined clinically and sent for various investigations. Investigations such plain abdominal X-Ray, serum electrolyte estimation, chest X-Ray and full blood count were carried out. The results of the investigations done were in keeping with the diagnosis of paralytic ileus, electrolyte imbalance and ongoing sepsis. She was subsequently managed through nil per oral, adequate fluid rehydration, antibiotics and correction of electrolyte imbalance. Following stable clinical state and investigation results, she was discharged and advised on follow-up.